Relative effects of xylazine-atropine, xylazine-atropine-ketamine, and xylazine-atropine-pentobarbital combinations and time-course effects of the latter two combinations on brain stem auditory-evoked potentials in dogs.
Brain stem auditory-evoked potentials (BAEP) were recorded in 4 dogs to analyze the relationship between acoustic stimulus intensities and peak latencies of each wave, and to investigate the relative effects of xylazine-atropine, xylazine-atropine-ketamine, and xylazine-atropine-pentobarbital combinations and the time-course effects of the latter 2 drug combinations on BAEP. Click stimulations fixed at a stimulus rate of 10/s and a frequency of 4 kHz were delivered at intensities ranging from 10- to 110-dB sound pressure level (SPL) in 10-dB steps for analyzing the relationship between the acoustic stimulus intensities and the peak latencies and at an intensity of 110-dB SPL for investigating the effects of the sedative and anesthetic drug combinations and their time-course effects on BAEP. Waves I to VI were identified with stimulus intensity of greater than or equal to 50-dB SPL. Wave VII was observed in some records, but was excluded from statistical analysis. As stimulus intensity was increased from 50- to 110-dB SPL, the latency decreased for all waves during xylazine-atropine-ketamine anesthesia. There were no statistically significant differences in the peak latencies of each wave in BAEP among xylazine-atropine, xylazine-atropine-ketamine, and xylazine-atropine-pentobarbital combinations 20 minutes after drug administration, except that the latency of wave VI during xylazine-atropine sedation was significantly (P less than 0.01) shorter than that detected during xylazine-atropine-ketamine or xylazine-atropine-pentobarbital anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)
Tokuriki
M
M
Department of Veterinary Physiology, Faculty of Agriculture, Yamaguchi University, Japan.
Matsunami
K
K
Uzuka
Y
Y
D000161:Acoustic Stimulation; D000818:Animals; D001285:Atropine / Q000494:pharmacology*; D001933:Brain Stem / Q000502:physiology; D004285:Dogs; D004338:Drug Combinations; D005072:Evoked Potentials, Auditory / Q000187:drug effects* / Q000502:physiology; D005260:Female; D007649:Ketamine / Q000494:pharmacology*; D007700:Kinetics; D010424:Pentobarbital / Q000494:pharmacology; D013843:Thiazines / Q000494:pharmacology*; D013997:Time Factors; D014991:Xylazine / Q000494:pharmacology*
D004338:Drug Combinations; D013843:Thiazines; D014991:Xylazine; D007649:Ketamine; D001285:Atropine; D010424:Pentobarbital